The Final Add-on for 恋爱关系/Romance has 15 achievements.
Open FINAL for the first time
Complete Chapter 8
Complete Chapter 9
Complete Chapter 10
Complete Chapter 11
Complete Chapter 12
Complete Ending 1
Complete Ending 2
Unlock special episode 1
Unlock special episode 2
Unlock special episode 3
Choose Nana-Hiroshu for the First Time
Choose Shinta-Chika for the First Time
Complete Chapter 13 twice
Get Understanding From Yuki